TY - JOUR
T1 - Kinetics of methane hydrate decomposition studied via in situ low temperature X-ray powder diffraction
AU - Everett, S. Michelle
AU - Rawn, Claudia J.
AU - Keffer, David J.
AU - Mull, Derek L.
AU - Payzant, E. Andrew
AU - Phelps, Tommy J.
PY - 2013/5/2
Y1 - 2013/5/2
N2 - Gas hydrate is known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Based on results from the decomposition of three nominally similar methane hydrate samples, the kinetics of two regions, 180-200 and 230-260 K, within the overall decomposition range 140-260 K, were studied by in situ low temperature X-ray powder diffraction. The kinetic rate constants, ka, and the reaction mechanisms, n, for ice formation from methane hydrate were determined by the Avrami model within each region, and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180-200 K was 42 kJ/mol and for 230-260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.
AB - Gas hydrate is known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Based on results from the decomposition of three nominally similar methane hydrate samples, the kinetics of two regions, 180-200 and 230-260 K, within the overall decomposition range 140-260 K, were studied by in situ low temperature X-ray powder diffraction. The kinetic rate constants, ka, and the reaction mechanisms, n, for ice formation from methane hydrate were determined by the Avrami model within each region, and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180-200 K was 42 kJ/mol and for 230-260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.
UR - http://www.scopus.com/inward/record.url?scp=84877040102&partnerID=8YFLogxK
U2 - 10.1021/jp4020178
DO - 10.1021/jp4020178
M3 - Article
C2 - 23557375
AN - SCOPUS:84877040102
SN - 1089-5639
VL - 117
SP - 3593
EP - 3598
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 17
ER -